Safety stop



"Jam. m3.

J ROBERTS SAFETY STOP. F1 LED JULY 14, I 921 mmm atented am. as, ice.

JAMES ROBERTS, F BUFFALO, NEW YORK.

SAFETY STOP.

Application filed July 14:, 1921.

r 6 New York, have invented certaininew and useful Improvements in Safety Stops, of which the following is a specification.

This invention relates to safety devices for woodworking and other machines in which wood or other material is fed into a machine and subjected to the action of rap idly rotating cutters, saws and similar tools. Tn machines of this character when the work is not securely held it often occurs that the contact of the tools with the work results in the violent throwing of the work from the machine and seriously injuring operatives or bystanders.

The purpose of the present invention is to provide an automatically operating stop, parts of which contact with the work, whereby when the latter is properly introduced into a machine any movement induced by the operation of tools tending to throw it from the machine will instantly be stopped and the work be held in a position to be quickly brought again into place to be operated upon.

Having this object in view, the invention consists of the safety device having the novel generic and specific features of construetion, combination and arrangement of parts, substantially as hereinafter described and claimed.

The preferred form of stop is illustrated in the accompanying drawing. In this drawing:

Figure 1 is a side view of a portion of a planing machine showing" my attachment applied thereto, the contacting dogs employed being shown by full lines in the positions assumed prior to the introduction of a material to be operated upon, and by dotted lines, the positions of the dogs when in op- 5 eration;

Figure 2 is a plan view showing a portion of one side ofa planing machine, the means for securing the attachment in place for use, and a portion of the dogs employed;

Figure 3 is a side view of a section of the shaft on which the contacting dogs are mounted and shape to the indentation.

Serial No. 4%,667.

Figure a is a side view of one of the contacting dogs; and

Figure is an end elevation of one of the dogs.

Tn the drawing 1 represents a portion of the side frame of a planing machine; 2

represents the work table; and 3 represents the feed roller by which the work is drawn into the machine.

Arranged above and extending transversely of the feed table, and held in a mannor to have a limited swinging movement, are a series of contact pieces or dogs 4:, of a number when placed side by side to extend entirely across the work table. Each dog is composed of a body 5 which is triangular in general contour having a curved toothed lower end a neck 6, and a hub 7. The hub has formed in one side a tapering indentation 8, and extending from the opposite side is a projection 9 which corresponds in size When the dogs are arranged in close relation to each other as in use, the projection from the hub of one dog enters the indentation in the next adjacent 'dog and thus all the dogs are maintained with their bodies in alignment.

The preferred form of support for the dogs is shown particularly in Figure 3 of the drawing. This consists of a hollow shaft 10 having a longitudinal slot 11 in the wall thereof, the width of the slot being somewhat greater than the size of the necks of the dogs, and the interior opening in the shaft being of a size to snugly hold the hubs of the dogs while permitting of their free swinging. Tn assembling the parts the hubs of the dogs are introduced into the open ends of the shaft and brought into close contact with each other with the projection from each hub entering the indentation in the next adjacent one. The contact ing faces of the indentations and projections are smooth, permitting free independent movement of the dogs and thus allowing the contacting ofrthe different dogs with the upper faces of work on the work table, of different thicknesses. Wren the dogs are arranged on the hollowshaft the necks 6 of the dogs extend through the opening formed by the slot 11, and the difference in the widths of the slot and the necks may be such that any predetermined extent of movement of the dogs independently of the shaft may be permitted.

In mounting the attachment the ends of the shaft 10 are secured to the sides of a planer or other machine in any suitable way, being preferably held by detachable brackets of a construction permitting. the ready raising and lowering of the shaft to adjust the height of the dogs to permit the passage beneath them of material of different thicknesses, and to compensate for wear on the dogs. The mounting herein shown is composedof standards 12 adapted to be secured to the sides of a machine, and brackets 13 secured to the standards and capable of vertical adjustment. Extending through openings in the standards are bolts 1 the head portions of which are received by vertical T-shaped grooves 15 in the brackets. This construction allows the quick elevation or depression of the brackets and of'their being firmly held in place by thebindingof the nuts 16 on the bolts against the faces, of the standards. Each bracket'l has in it an opening 1'? into which the shaft 10 projects, and when the position of the shaft in. respect to its longitudinal slot is determined, the shaft is secured by means of the set screws 18 passing throughthe brackets and bearing on the shaft.

One or both ends of the shaft has secured in it a plug 19, the outer end of which is angular in cross section, so that by loosening the set screws and ap 'ilying a wrench to the plug the shaft may be turned to bring the slot in the shaft to a position properly to position the dogs carried by the shaft.

In the use of the attachment material to be operated upon is pushed into the machine and as it contacts with the dogs the latter are swung inward/and are held by gravity to bear with the ends of their curved toothed faces on the upper face of the material. The thickness of the material allowed to be introduced is determined by the position or Width of the slot in the shaft through which the necks of the dogs extend, the admission of work too thick to be properly operated upon by the machine being checked by contacting of the dogs with the edge of the slot in the shaft causing the dogs to act as a barrier against the introduction of the material. ll ith the dogs resting on the upper faoeof the work as described, any back movement induced by the operation of the machine will cause the dogs to turnon their hubs bringing the curved toothed ends of the dogs to positions instantly to bind the work to the work table and thus prevent ejection of the work from the machine.

I claim:

1. A safety device of the kind described comprising a plurality of rotatable dogs adapted to contact with material to be op-- erated upon, a tubular shaft having a longitudinal slot therein. a portion of each dogbeing held movably in the opening in the shaft, and a part thereof adjacent to the held'portion extending through the slot. and means for mounting the shaft and for adjusting its elevation and the position ol its slotted portion.

2. A'safety device of the kind described con'iprising a plurality of rotatable dog's adapted to contact with material to be operated upon, a tubular shaft having a longitudinal slot therein, a portion. of each dog being held movably in the opening in the shaft, and a part thereof adjacent to the held portion extending through the slot. vertically adjustable brackets having openings receiving the ends of the shaft, and means for adjustably holding the shaft in the openings.

3. A. safety device of the kind described comprising a plurality of rotatable dogs adapted to contact with material to be 0 erated upon, a tubular shaft having a longitudinal slot therein, a plug having an angular exposed end secured inv the end of the shaft, and vertically :uljustablc brackets having openings forming hearings for the shaft and means for detachably scour-- ing' the shaft in the openings.

-i-.. A safety device of the kind described comprising dogs each having a body with a curved end adapted to bear on material to be operated upon. the other end being provided with a cylindrical hub having in one side a circular indentation and on the Other side a projection of a form corresponding to that of the indentation. and means for mounting the dogs inchiding a tubular slotted shaft, the hubs of the dogs being located in the opening in the shaft and the portions of the bodies of the dogs adjacent to the hubs extending through the slot, and means for mounting the dogs including a tubular slotted shaft. the hubs of the does being located in the opening in the shaft and the portions of the bodies ol' the dogs adjacent to the hubs extending through the slot.

In testimony whereof l ture.

aim; my signa- 

